The cost of food. However, before you get into the details of how to lower your grocery bill, always define the costs of your food. Food costing is generally used by professional cooks to determine their budget for food for a given week.
Make a simple price book to determine which store near you has the best prices. The easiest way to do this is to identify the fifteen to twenty-five most common things you buy, then shop at a bunch of different stores and compare the prices on these items. The store with the lowest average price on the things you buy should be the store you shop at regularly. I was surprised when I did this test myself, because I discovered that the store I thought was low priced was far from the least expensive option on the stuff I actually bought routinely.
Make a meal plan. Plan out what you’ll eat a week in advance before you leave for the grocery store. Know the next seven breakfasts, lunches, and dinners you’ll have, then make sure you have all of the ingredients for them. If you don’t, add that ingredient to the shopping list (it’s right on your fridge, right?).
Enjoy your shopping!